Primary Partition On A Hard Drive Must be Active! Why?

Why must the primary partition on a hard drive be active?
The primary partition must be set to a status of Active, otherwise it is not possible to boot off that primary partition. Please note that only the primary partition on the primary Master drive can be set to a status of Active.

To check whether your partition is active, or to activate the partition if it is not active, use FDISK.

1. Boot your system with a Windows startup disk and type FDISK at the A: prompt and press ENTER.
2. If your partition is not active, you will see a warning message at the main menu of FDISK stating Warning – No active partitions set at the bottom of the screen.
3. To set the partition as active, select 2 Set Active Partition and choose Partition 1 when prompted to select the partition.